Rectifier



Junegs, 192s,

W. G. HETTICH RECTIFIER Filed Jan. 30, 1926 Patented June 26, 1928.

UNITED STATES PATENT OFFICE.

WILLIAM G. HETTICH, F CHICAGO, ILLINOIS, ASSIGNOR TO STANDARD X-RAY COH- PANY, 0F CHICAGO, ILLINOIS,

A CORPORATION OF ILLINOIS.

RECTIFIER.

Application led January 30, 1926. Serial No. 84,958.

4 alternating electricV current and particularly to a mechanical rectifier. One object of my invention is the provisionof a rectifier in which the energy vloss due to the resistance of the air at the spark gap is reduced to a minimum. Another object is the provision of means for immobilizing or holding the air ionized by the electric discharge or current passage across the gap. Another object is the provision of means for minimizing the eii'ect of the windage of the rotating parts in increasing resistance across the air gap. Other objects will appear from time to time in the course of the specication and claims.

I illustrate my invention more or less diagrammatically in the accompanying drawings, wherein- Figure l is a diagrammatic showing of my rectiier shown as employed with a Coolidge tube;

Figure 2 is a side elevation of the rotating parts and fixed contacts with yparts in section;

Figure 3 is an enlarged section through one of the fixed contacts or brushes; and

Figure 4 is a plan view of the structure of Figure 3 with parts inl section.

Like members are illustrated by like characters throughout vthe specification and drawings.

A is any suit-able driving member, preferably a synchronous motor, revolving in synchronism with the alternations of the alternating current employed. A1 is any suitable shaft, preferably of bakelite or similar Ainsulating material, adapted to be rotated b Vand in vsynchronism with the motor A.

ounted on it is a disc A2, preferably o bakelite or some other suitable insulating material. The supports and bearings for the rotating parts are not indicatedl since they form no part of the present invention. Mounted about the periphery of the disc A2' at any suitable interval, for example at 90 intervals, are the contacts or brushes A's A,4

I disc.

Mounted about the disc A and also posiinvention relates to a rectifier of antioned at 90 intervals are a plurality of lixedcontacts or blades B, B1, B2 and B3. Each such blade is associated with or mounted in a hollow casing B4, the casing having an open mouth B5, in which the blade is set, the mouth having at each side the inwardly projecting lips or walls B6 which may, if desired, project inwardly toward the disc, even to the point of overlapping the blades A3 A?. 'lhehollow interior of each member B4 preferably communicates with the outer air only through the mouth B5.

Whereas in practice I may wish to employ more than'one disc, I have illust-rated a rectierin which but one disc is shown, and I do not wish to be limited to any specific.

number of discs, orto any specific spacing of t-he bruslies or contacts about the discs.

C generally indicates any suitable transformer which may include for example the laminated iron core C1, about one arm of which, C2, is wound the primary coil C3. The primary coil C3,may be in circuit with any suitable auto transformer, generally denominated asl), the details of which form no part of the present invention. D1 D2 represent4 the conductors of the alternating current circuit.

The opposite arm C* of the core has wound about it the secondary coil C5. Thecircuit may extend from the brush or blade B along the conductor E to the coil C", thence along the conductor lilL to the blade B2, or the line within the casing E may be omitted, the casing Bbeing formed of conductive material. 'From the blade B1 the conductor E2 may extend for example to the Coolidge tube generally denominated as G. From the opposite terminal of the Coolidge tube extends the conductor Es tothe fourth blade Bs. Gr1 is any suitable conductor extending to the filament of the tube, to complete the filament heating circuit. l

It will be realized that whereas I have described and shown a practical and operativer I employ a mechanical rectifierl including an insulated disc with two pairs of brushes or contacts or blades mounted about its periphery, the individual blades beincr spaced at 90 intervals. The motor is sync ronized f with the alternations of the current supply.

In the operation of my device' herein illustratively shown I maydeliver a.220 volt alternatin current to the auto transformer. The trans ormer may deliver an alternating current of say from 7 5l to 220 volts to the primary coil of the X-ray transformer. The secondary coil may deliver an alternating current of say from 30 to 100 kilovolts in the circuit including the brushes or blades B and B2. The Coolidge tube is included in the circuit including the fixed bladesl1 B3.

As the motor rotates in synchronism with the alternations of the current, a pulsating direct current of 30 to 100 kilovolts or more is paed through the Coolidge tube. Ob-

` viously these figures are merely illustrative.

As the current passes across the ap be'- tween' the fixed and the movingy blades, the air, which is normally a good insulator,i3 ionized by the passage of the current, and becomes a good conductor to the extent that it is ionized, That is' to say, the air across the gap is filled with free electrons, the atoms ing broken up. The ionization of the air gap involves a definite energy loss and it 1s one purpose of my invention to minimize this loss by conserving the already ionized .the brushes or gaps.

I claimr' 1. In a line of current transmission including an air gap, opposed fixed' and moving brushes, and means for holding about said air gap the air ionized by the'passage of current thereacross com rising a'housin associated with the fixed trust, said fixed brush being mounted in the mouth of said I housing, the housing enclosing a vfdead air space.

2; In amechanical rectifier, a disc and means for rotating it, a. plurality of brushes mounted on said disc and spaced. about its periphery, a plurality. ofvxed brushes positioned about said disc, means for passing a purrent across said fixed and moving brushes,

between said' .fixed and moving brushes the air ionized by the passage of current thereacross.

3. In a mechanical rectifier, a disc and means for rotating it, a plurality of brushes mounted'on said disc and spaced about it", periphe a plurality of fixed brushes positioned a out said disc, means for passing a current across said -xed and moving brushes, and means for holding about the air gaps between said fixed and moving brushes the air ionized by the passage of current thereacross comprising `housings associated with the fixed brushes.

4. In a mechanical rectifier, a disc and means for rotating-it, a plurality of brushes mounted on said disc and spaced about it; periphery, a pluralityof lixedbrushes positioned about said disc, means for passing a current across said fixed and moving brushes, and means for holding about the air gaps between said fixed and moving brushes the air ionized' by the passage of' current thereacross comprising housings associated with the fixed brushes, fixed brushes beingl mounted in the mouths of said housand means for holding about the air gapsl ings, the housings enclosing each a dead'air space.

5. In a rectifier which includes a -plurality of lines of current transmission'each formed bya plurality of relatively movable conductive members having an air gap therebetween, a rotor, members thereon, a plurality of fixed conductive members positioned about said rotor a plurality of conductive and in line with the conductivemembers. on I said rotor, and open mouthed housings, associated with each such fixed conductor, for holdin about it the air ionized by the passage o current across the gap between the fixed and movino conductive members, the fixed members beinginl the form of blades,

lying in the general plane of the rotor, andv positioned wlthin the .housing mouths.

6. .In a linev of current transmission in Vcludlng an air gap opposed fixed and moving brushes and means for holdingabout said air gap the air ionized by the passage of current thereacross, comprising a housing associated with the fixed brush, the housing enclosing a dead 'air space.

Signed at Chicago, county of Cook State of Illinois', this 25th day of January, 

